# ---
# title: 415. Add Strings
# id: problem415
# author: Tian Jun
# date: 2020-10-31
# difficulty: Easy
# categories: String
# link: <https://leetcode.com/problems/add-strings/description/>
# hidden: true
# ---
# 
# Given two non-negative integers `num1` and `num2` represented as string,
# return the sum of `num1` and `num2`.
# 
# **Note:**
# 
#   1. The length of both `num1` and `num2` is < 5100.
#   2. Both `num1` and `num2` contains only digits `0-9`.
#   3. Both `num1` and `num2` does not contain any leading zero.
#   4. You **must not use any built-in BigInteger library** or **convert the inputs to integer** directly.
# 
# 
## @lc code=start
using LeetCode

## add your code here:
## @lc code=end
